Popover with ModalPresentationStyle is not centere

问题:

I have a problem with iOS 7 that seems to be a bug or I just don't do something right. I have modalViewController that appears as a popover on iPad with ModalPresentationStyle. And it is not standard size, custom sized. Here is the code:

myViewController *myVC = [[myViewController alloc] init];
UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:myVC];
[nav setModalPresentationStyle:UIModalPresentationFormSheet];
[nav setModalTransitionStyle: UIModalTransitionStyleFlipHorizontal];
[self presentViewController:nav animated:YES completion:nil];
nav.view.superview.bounds = CGRectMake(0, 0, 320, 465);

It's all working fine in iOS 6, but in iOS 7 it's not centered. But if I set ModalTransitionStyle to UIModalTransitionStyleCrossDissolve it works fine. But only in this mode. Maybe someone stumbled on this one too and know how to fix it? I'm not a big fan of dissolve effect. Thank you.

回答1:

I have a method where the old custom modal presentation style fromsheet works with iOS <=7 although you might set custom height and width.

Keep in mind that this method might not work in any newer version in the future

- (void) hackModalSheetSize:(CGSize) aSize ofVC:(UIViewController *) aController;
{

    void (^formSheetBlock) (void) = ^{
        int preferredWidth = aSize.width;
        int preferredHeight = aSize.height;

        CGRect frame = CGRectMake((int) 1024/2 - preferredWidth/2,
                                  (int) 768/2 - preferredHeight/2,
                                  preferredWidth, preferredHeight);
        aController.view.superview.frame = frame;
        if([aController respondsToSelector:@selector(edgesForExtendedLayout)]) { //ios7
            aController.view.superview.backgroundColor = [UIColor clearColor];
        } else { // < ios7
            UIImageView *backgroundView = [aController.view.superview.subviews objectAtIndex:0];
            [backgroundView removeFromSuperview];
        }
    };

    //on ios < 7 the animation would be not as smooth as on the older versions so do it immediately
    if(![self respondsToSelector:@selector(edgesForExtendedLayout)]) {
        formSheetBlock();
        return;
    }

    double delayInSeconds = .05;
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);

    dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
        formSheetBlock();
    });
}

回答2:

I had the same problem. I have solved this by using another approach, found here.

What this solution proposes is to use the method (void)viewWillLayoutSubviews

So in case of @Manuel M. inside the GeneralSettingsViewController add the code below:

// GeneralSettingsViewController
- (void)viewWillLayoutSubviews{
    [super viewWillLayoutSubviews];
    self.view.superview.bounds = CGRectMake(0, 0, 497, 375);
}

And you won't need this code anymore:

self.generalSettingsVC.view.superview.frame = CGRectMake(0, 0, 497, 375);
self.generalSettingsVC.view.superview.center = self.view.center;

For @titicaca, you are using a UINavigationController I haven't test it with this Controller but you could try the same solution I mentioned, extending the UINavigationController and overwrite the viewWillLayoutSubviews method.

[EDIT]

For @titicaca I tried it in a new project and for me it worked. What I did was having a custom navigation view controller CustomNavigationController overriding the viewWillLayoutSubviewslike this:

- (void)viewWillLayoutSubviews{
    [super viewWillLayoutSubviews];
    self.view.superview.bounds = CGRectMake(0, 0, 330, 284);
}

Then, the view controller that presents the CustomNavigationController should execute a code similar to this:

UIViewController *myVC = [[UIViewController alloc] init];
[myVC.view setBackgroundColor:[UIColor redColor]];

CustomNavigationController *nav = [[CustomNavigationController alloc] initWithRootViewController:myVC];
[nav setModalPresentationStyle:UIModalPresentationFormSheet];
[nav setModalTransitionStyle: UIModalTransitionStyleFlipHorizontal];

[self presentViewController:nav animated:YES completion:nil];

You need to make sure though, that the dimensions of the self.view.superview.bounds = CGRectMake(0, 0, 330, 284); are even numbers otherwise the text inside gets fuzzy, if there is any

回答3:

For me the issue was calling becomeFirstResponder on a text field in the viewDidAppear of the presented view controller. Appears to be a bug with that now. The solution was wrapping it in a simple dispatch_async:

- (void)viewDidAppear:(BOOL)animated
{
    [super viewDidAppear:animated];
    dispatch_async(dispatch_get_main_queue(), ^{
        [self.userNameTextField becomeFirstResponder];
    });
}

回答4:

It's the same for me... I don't know yet how to solve it. I'm currently working in that issue so anything I get I'll share it!

This is my code.

-(IBAction)showGeneralSettings:(id)sender{

self.generalSettingsVC = [[GeneralSettingsViewController alloc] initWithNibName:@"GeneralSettingsView" bundle:nil];

//Present the view controller as a modal with a custom size (important to do after presenting it)
self.generalSettingsVC.modalPresentationStyle = UIModalPresentationFormSheet;

[self presentViewController:self.generalSettingsVC animated:YES completion:nil];

self.generalSettingsVC.view.superview.frame = CGRectMake(0, 0, 497, 375);
self.generalSettingsVC.view.superview.center = self.view.center;

}

回答5:

The solution above did not work for me. I used the following:

      UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:theViewController];
      navigationController.modalPresentationStyle=UIModalPresentationFormSheet;
      [self presentViewController:navigationController animated:YES completion:nil];
      if([[UIDevice currentDevice] userInterfaceIdiom] != UIUserInterfaceIdiomPhone){
            navigationController.view.superview.frame = CGRectMake(0, 0, 320, 544);
            navigationController.view.frame =CGRectMake(108, 0, 320, 544);
            navigationController.view.superview.backgroundColor=[UIColor clearColor];
      }

回答6:

I went about this slightly differently using a subclassed navigation controller and AutoLayout in Swift, to center the view in the superview at a set width and height. My particular case needed iPad and iOS7-8 support (there's some constants specific to my project in this code, but you get the idea) ...

class CenteredModalNavigationController: UINavigationController {

    // MARK:- Methods

    override func viewDidLoad() {
        super.viewDidLoad()
        preferredContentSize = CGSizeMake(320, 480) // iOS8 only
    }

    override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated)

        // iOS7 support for iPad custom sized form-sheet modal.
        if kDeviceiOS7 && kDeviceiPad {
            if view.superview == nil {
                Log.warning("Failed to find superview")
                return
            }
            view.superview!.setTranslatesAutoresizingMaskIntoConstraints(false)

            // Give the superview constraints to center the view inside it.
            var viewBindingsDict: NSMutableDictionary = NSMutableDictionary()
            viewBindingsDict.setValue(view, forKey: "view")
            viewBindingsDict.setValue(view.superview!, forKey: "superview")
            let centerXConstraints = NSLayoutConstraint.constraintsWithVisualFormat("V:[superview]-(<=1)-[view]",
                options: .AlignAllCenterX,
                metrics: nil,
                views: viewBindingsDict)
            view.superview!.addConstraints(centerXConstraints)

            let centerYConstraints = NSLayoutConstraint.constraintsWithVisualFormat("H:[superview]-(<=1)-[view]",
                options: .AlignAllCenterY,
                metrics: nil,
                views: viewBindingsDict)
            view.superview!.addConstraints(centerYConstraints)

            // Now give it a width/height and it should float in the middle of our superview.
            AutoLayoutHelper.addWidthConstraint(view,
                aSuperView: view.superview!,
                width: 320)
            AutoLayoutHelper.addHeightConstraint(view,
                aSuperView: view.superview!,
                height: 480)
        }
    }

    override func prefersStatusBarHidden() -> Bool {
        return true
    }

    override func disablesAutomaticKeyboardDismissal() -> Bool {
        // DEVNOTE: Because this is shown in a modal, this is required to stop keyboard dismiss issues.
        return true
    }

}

...

class AutoLayoutHelper: NSObject {

    class func addHeightConstraint(aChildView:UIView, aSuperView:UIView, height:CGFloat) {
        var constraint = NSLayoutConstraint(item: aChildView,
            attribute: NSLayoutAttribute.Height,
            relatedBy: NSLayoutRelation.Equal,
            toItem: nil,
            attribute: NSLayoutAttribute.NotAnAttribute,
            multiplier: 1.0,
            constant: height)
        aSuperView.addConstraint(constraint)
    }

    class func addWidthConstraint(aChildView:UIView, aSuperView:UIView, width:CGFloat) {
        var constraint = NSLayoutConstraint(item: aChildView,
            attribute: NSLayoutAttribute.Width,
            relatedBy: NSLayoutRelation.Equal,
            toItem: nil,
            attribute: NSLayoutAttribute.NotAnAttribute,
            multiplier: 1.0,
            constant: width)
        aSuperView.addConstraint(constraint)
    }

}